It's one of my favorite singers of the sixties (and the seventies and the eighties, etc…and my friend Shelly Goldstein and I even went to see her perform just a few years ago), Petula Clark. Here she is with her 1966 hit, "My Love." I don't know where this video is from but it's obvious she's lip-syncing to the record. No one bothered to dub in audience sounds when they're clapping.
Also, she obviously did the number a couple of times — probably only once in front of the live audience — and someone edited different takes together. Every time they cut from one angle on her to another, her hands are in a different position. But who cares? It's Petula…